robert anthony hardcastle



,geiten taten gat-trat @fitta ROBERT ANTHONY HARDCASTLE, OF NEWCASTLEsON-TYNE, ENGLAND; Letters Patent No. 64,527, dated Mey 7, 1867.

IMPROVEMENT IN DIFFERENTIAL PULLEY-BLOGKS.

TO ALL WHOM IT MAY CONOERN:

Be it known that I, Ronnn'r ANTHONY HAnncAsrLn, of the town and cou'nty of Newcastle-on-Tyne, England, have invented or discovered certain new and useful Improvements in Apparatus for Raising and Lowering. Heavy Bodiesgf and I, the said ROBERT ANTHONY H-ARDCASTLE do hereby declare the natureV of the said invention, and in what manner' the same is to be performed to be particularly described and ascertained in and by the following statement thereof, that is to sa l My said invention relates to certain improvements upon and modifications of the pulleys known as Westons differential pulley-blocks, for which Letters Patent were granted to Thomas Aldridge Weston, bearing date the 25t v April, 1859, No. 1033, and has for its object the affording-of greater facility for coupling and uncoupling the sheaves, whereby the distance between the xed block and the's'natch block can bel adjusted at any time so as to vary the range of lift at will, and weights may be moved with greater rapidity than can be effected by 4the dierential pulley-blocks above referred to; the same apparatus possessing all the advantages of the di'erential pulley-block when used as such. According to my present invention I propose to make the two sheavesv of the dilt'erential pulley-block separate from each other', and to couple or uncouple them by means of a sliding clutch or by using a slidingsheave, and to provide one or both the sheaves with pins, cogs, or other projections which engage with or into lcorresponding projections, holes, or depressions formed on or made in the contiguous face of the adjoining sheave, or the two sheaves may be coupled together by forcing the one against the other laterally by means of a wedge, inclined plane, or spiral thread or threads acting upon the sliding sheave. By the means above referred to, great facility is afforded for coupling or uncoupling the sheaves, whereby the same pulley-block is rendered capable of being used either as a diii'erential'nulley-block, by coupling the two sheaves together, eras an ordinary block, by unco'upling or disengaging the sheaves from each other, in which latter case if one of the sheaves be locked so as to prevent it from turning round it would hold fast that portion l of the chain running over it, and enable theattendant, by holding on to the opposite portion of the chain running over the loose sheave, to raise or lower weights in the same manner'as with an ordinary block. Thisv locking ot' one of the sheaves can either be separately effected or it may be effected by an extension of.v the same contrivances which serve to uncouple the sheaves.

And in order that the said invention may be fully understood, Ivshall now proceed more particularly-to describe-the same, and for that purpose I shall refer lto'the several figures on the annexed sheet of drawings, the same letters of.reference indicating corresponding parts in all the gures.

Figure I of my drawings represents a front elevation of differential pulley-block, whereinthe coupling and uncoupling'of thesheaves is eifected by a sliding clutch; and

Figure 2 is a corresponding side elevation of the same looking inthe direction of the arrow in g. l.

A and 5 represent respectively the larger and smaller sheaves of the block, which in all cases should have their peripheries so formed as to prevent the surging or slipping of theendless chain X Y over them. Y The sheave A runs looseon the spindle C, and the sheave b is keyed or otherwise made fast thereon, an enlargement or shoulder, d, being formed on the spindle in order to keep the sheaves in' their places. e is a clutch-box, sliding along the part d of thespindle and prevented from turning thereon by the key g. This clutch isvprovided with one or lmore pins or other projectionsf'which enter corresponding holes or depressions in the face of the sheave A when the coupling is eifected. L is a lever, carried by the frame of the block for throwing the sliding clutch e in or out of goal-with the sheave A, and z' is a spring, which may be used, if found desirable, for maintaining the clutch in ge'ar. A cord, 7s, attached to the lever t, and passing over a guide-pulley in thc frame, descends to withinv easy reach of the hand of the operator, who, on pulling the cord, can at any moment throw 'the clutch out of gear with the sheave A, whereupon the sheave A will be left free to revolve on the spindle e independently of the sheavel ABy locking the sheave Z5, by means of the pawl Zcarried by the frame, and engaging into the ratchet-wheel m fast on the spindle, or into teeth formed on the sheave itself, the portion y of the chain will be held fast, whilst the other portion fc, passing over the loose sheave a, may be hauled upon or let go, as the case may be, for thc purpose of raising or lowering light weights with rapidity. On releasing the (ord c the spring' will throw the clutch c in gear with the sheave a, when, as the two sheaves will then rotate together with the spindle c, the arrangement may be used in the saule manner as a differential pulley-block. As the pawl-Z will only allow the sheaves to revolve in the direction -i'or lowering a weight by the dierential action, it will be necessary to throw it out of gear with aratchet-wheel, m, shouldit berequired to hoist dierentially. It' the pulleys be reversed, and I locked, it willvbe seen that the pa-wl will have to be thrown out of gear to lower differentially. In thearrangement last described, it will be seen that neither of the sheaves slides laterally, and that theeouplin'g and unco'upling is eti'ected solely by a sliding-clut'ehbox. In the modieation illustrated by Figures 3 and 4 the sheave a is caused to slide to and from the sheave b, along the spindle c, by the same means as those described for sliding the clutch in the rst arrangement, the lever L being caused tol engage in a groove in the boss of the sliding sheave Both the sheaves a and 6 maybe looseen the spindle c, or one of them may betast or caused to revolve therewith'wihilst the other is loose thereon. The coupling'of the two sheaves is inv this modification effected by the pin or'projectionfin one sheave entering a corresponding hole in the other sheave when the two are brought together.

Figure 3 represents the two-sheaves coupledtogether and'operating as a differential pulley-block; and

Figure 4 shows them uncoupled or disengaged from each other.

The locking of the sheave a is effected by the mere act of uncoupling, a stud or pin, z, in the frame, being caused to enter an aperture in the sliding sheave as it is being withdrawn from the other one, and so locks it, and holds fast the part o: of the endless chain, whilst the party is free to be hauled or'let go over the pulley 'I1 for raising or lowering a weight with rapidity.

Figures 5 and 6 illustrate a third modieation, wherein the sheaves a and b are coupled or geared together by the mutual interlocking of a series of inclined or wedge-shaped projections or ratchet-teeth, s and p, formed on the contiguous Afaces oi' the two sheaves respectively, the locking of one of the sheaves being also effected by' inclined projections q, on the outer face of the sheave, engaging with a corresponding inclined projection, z, formed 'on or itted to a convenient part of the frame of the block. In this modification, as in the onelast described, the same movement which serves-to uncouple the sheaves locks one'of them, but the coupling and vuneoupling of" the two shea-vesand the locking Aand releasing ofv one of them is eected by the ordinary endless chain attached to the block, the separate cord k, lever h, andspring z' being dispensed with.

Figure 5 shows the sheaves a 6 uncoupled and the sheave a locked; and

Figure 6 shows the same sheaves coupled or engaged together and acting as differential pulleys` The inclined projections s and y, which are formed on the inner faces of the sheaves a and b respectively, are made to lock into each other in such a way that the weight suspended from the snatch block zu tends to 'keep them so locked or coupled together, as shown in iig. 6. The sheaves a and Zz being thus coupled, by hauling on the part :v of the chain the weight will be lifted, and by hauling on the part y of the chain the weight wilt be lowered differentially, but by hauling on both parts a: and y et`- the endless chain simultaneously with sufli`n cient force to overcome the gravity of the weight, the inclined projections s andjo would slide or pass over each other, and thereby force or wedge the sheave a partly into the fixed stop e, with which one of the series of .inclined projections q becomes engaged, whereupon the said sheave will be locked or prevented from turning in one direction and will consequently hold fast the part x of the chain where it passes over the said sheave. By continuing to haul on the part y of the chain, the sheave a will be completely engaged or locked with the-stop z, and wholly uncou'pled or disengaged from the sheave 6. In this condition of the pulley the weigh-t canbe readily raised or lowered with a power oftwo to oneby the portion y of the chain and the sheave b. In lieu of hauling on both Aparts x and y of the chain simultaneously for the purpose of uneoupling the sheaves, this may be accomplished by making fast one part ot' the chain and hauling on the other. It will be seen on referring te the drawing that the sheave a cannot be uncoupled'from the sheave b without being at the same time locked 1 or engaged with the fixed stop z; also that it is impossible for the operator to uncouple the sheaves when acting differentially unless he has power of lifting the weight; hence no risk is incurred of the operator being overpowered on uncoupling the sheaves when acting differentially, as more power will be required to effect such uncoupling than to sustain the weight when the sheaves are uneoupled. The two sheaves, when separated or uncoiipled, can again be brought together and coupled byV hauling on the parts x and y of the chain.

Figures 7 and 8 illustrate another modification, wherein the sheaves a and 6 are eoupledand uncoupled by moving one of them laterally by hand along the spindle c, each sheave being provided with one or more projections sp, the projections s onI one sheave locking against the projection p on the other sheave. The projections g and z-ser've to lock .the sheave a when uncoupled.

Figures 9 and l0 illustrate another modification for coupling and uncoupling the sheaves a and b, iig. 9. showing the sheaves uncoupled, and iig. 10 coupled. In this arrangement an inclined plane in the form of a .Vl spiral thread or threads is employed as the medium forfcoupling and uncoupling the sheaves, the requisite motion of the parts for eifecting such operations being as in the arrangement shown at figs. 5 and 6, derived solely from the ordinary endless chain passing over the sheaves of the block. The spindle c is provided with spiral threads er projections p, which enga-ge into corresponding spiral grooves made inside' the centre of the sheave a, whilst the sheave b is fast on the spindle t'. On hauling both parts 'x and g/ of the slack portions of the chain simultaneously, the sheaves will bedseparated by the action of the spiral thread, (see iig. 9,) until the sheave ais moved entirely sufficiently far to be locked by the inclined projections gend V2, as in figs. 5 and 6, and to beV released from the spiral threads or projections p. In this condition the sheaveb with its spindle is free to rotate independently of the sheave u, and-the block maythen be employed for expeditiously raising or lowering light weightsA with a purchase'of twotio one. The sheaves when separated may again be coupled by haulingon the a A parts :c andy of the chain, when .the inclined projections g and z will7 by sliding over each other, force the Q sheave ein Contact with the spiral threads p. By now releasing the part of the chain, the weight at w will l rotate the spindle e and cause the spiral thread to enter the sheave d, and-so tighten the two together, as in g.

I0, when the dili'crental action will be resumed'. I

Figure-11 represents a sectional elevation of another modification, wherein the results hereinbefere referred to are obtained by the use of a sliding clutch in lien of a slidi-n-gor laterally adjustable sheave, such clutch being thrown in and out of gear with one of the two sheaves so as to couple and uncouple the same, and-simultaneouslylocking the larger pnlleya and releasing it again by the sole action of the ordinary endless chain, in the manner hereinbefore described in reference to figs. 5 and 6 of my drawings. a is the larger sheave; the

-smaller one; and c the spindle or axis of the same. Upon this spindle c revolves freely the sliding clutch e, a

detail elevation of which is shown at Figure 13. This clutch is made square, or of such other forni at the part g, where it enters the slieave a, as willprevent the said sheave from turning on the clutch. s are inclined prov jections or ratchet-teeth formed on one end of the clutch, which engage with corresponding ratchet-teeth on the inner face of the smaller sheave On the opposite end of the clutch e there is formed a series of inclined projections or ratchet-teeth, g, which, when the clutch is disengaged from the sheave ZJ, become ld'cked or 'engaged with a correspondingly shaped or inclined catch or stop, e', formed on the interior of the frame of theblock. The direction of inclination of the several teeth or projections 3,22, g, and e, is the sameV as illustrated by figs. 5 and 6, and hence the coupling and u ncoupling of the sheaves and the locking of one of them may be effected by the chain itself, in the manner already described, the only diierence being that in lieu of the sheave a moving laterally under the operation of the inclined projections, it is the clutch e which receives that motion and slides freely inside the sheave a. It will be readily seen that although in igs. 3 to 12 the large sheave slides and locks, the same operations can be performed if the small sheave is made to slide and lock.

Having now described and particularly ascertained the nature of n iy said invention, and the manner in which the same is or may be used or carried into effect, I would observe in conclusion that I am aware that it has already' been proposed to employ separate or divided sheaves capable of independent action in what are known as Westons differential pulley-blocks with a View to lowering weights, and also that it has. been proposed, where three or more sheaves are employed in a diiferential lpulley-blocl:, to make one of them capable of being disconnected from the rest with a view solely to enable more or less chain to be taken in or let outv from such loop in order to vary the range of lift, and therefore I do not claim as of my invention the use in differential pulley-blocks of a sheav'e capable of being disconnected from the adjoining sheave or sheaves, ner do I claim every mode of coupling and uncoupling such sheaves; but what I consider as novel and original, therefore claim as the invention secured to me by the hereinbefore in part recited Letters Patent, is-

1. The application and use of a sliding clutch for the purpose of coupling and uncoupling the sheaves in differential pulley-blocks, substantially in the manner hereinbefore described and illustrated by Iig. 1 of my drawings.

i 2. The application and use of a sliding clutch for the purpose both of coupling andlnncoupling the sheaves in differential pulley-blocks, and of locking one of such sheaves, as hereinbefore described and illustrated by ligs. 11, 12, and 13 of my drawings.

3. The'applica-tionand use of lateral cogs, pins, projections, or teeth on one'sheave, in combination with a fixed stop .or catch on the frame ofthe pulley-block, both for the purpose of coupling and uncoupling the sheaves in diiiferential pulley-blocks, and simultaneously locking one of such sheaves, substantially as and for the purpose hereinbefore described and illustrated by figs. 3, 4, 5, 6, 7, and 8 of my drawings.

4. The application and use to and in di'erential pulley-blocks of a sliding clutch or a sliding sheave, in combination with a lever, cord, wedge, or spring, for producing the necessary motion for coupling and uncoup= ling, or for coupling, uncoupling, and locking the sheaves, substantially as h'ereinbefore described and illustrated by figs. 1, 2, 3, and lof my drawings.

5. The application and use in differential pulley-blocks of one or more spiral projections or threads formed on the' spindle or axis of the sheaves, and being in combination with inclined teeth or projections on one ofthe sheaves and on the frame on the pulley-block, for the vpurpose both of coupling and uneoupling the'sheaves, and of locking one of such sheaves, as hereinbefore described and illustrated by gs. 9 and 10 of my drawings.-

R. A. HARDcAsTLn.

Witnesses:

THEO. WOOD BUARING, Grey Street, lVweaetZc-upon-Tyne, Engineer. ISAAC! PATTINSON, J r., No. 3 Dean Street, Newcastle-upon-Tyne, Law Student. 

